Bruce Momjian <pgman@candle.pha.pa.us> writes:
> Neil Conway wrote:
>> In general, I don't think this is worth doing.
> It is possible it isn't worth doing. Can the INSERT/DELETE
> incrementing/decrementing the cached count work reliabily?
I don't even see how the notion of a single cached value makes
theoretical sense, when in principle every transaction may have
a different idea of the correct answer.
You could doubtless maintain a fairly good approximate total this
way, and that would be highly useful for some applications ...
but it isn't COUNT(*).
regards, tom lane